Loading by xmodem through console port, Introduction to xmodem, Loading boot rom – H3C Technologies H3C S3100 Series Switches User Manual
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Loading by XModem through Console Port
Introduction to XModem
XModem protocol is a file transfer protocol that is widely used due to its simplicity and high stability. The
XModem protocol transfers files through Console port. It supports two types of data packets (128 bytes
and 1 KB), two check methods (checksum and CRC), and multiple attempts of error packet
retransmission (generally the maximum number of retransmission attempts is ten).
The XModem transmission procedure is completed by a receiving program and a sending program. The
receiving program sends negotiation characters to negotiate a packet checking method. After the
negotiation, the sending program starts to transmit data packets. When receiving a complete packet,
the receiving program checks the packet using the agreed method. If the check succeeds, the receiving
program sends acknowledgement characters and the sending program proceeds to send another
packet. If the check fails, the receiving program sends negative acknowledgement characters and the
sending program retransmits the packet.
Loading Boot ROM
Follow these steps to load the Boot ROM:
Step 1: At the prompt "Enter your choice(0-9):" in the BOOT Menu, press <6> or <Ctrl+U>, and then
press <Enter> to enter the Boot ROM update menu shown below:
Bootrom update menu:
1. Set TFTP protocol parameter
2. Set FTP protocol parameter
3. Set XMODEM protocol parameter
0. Return to boot menu
Enter your choice(0-3):
Step 2: Press 3 in the above menu to download the Boot ROM using XModem. The system displays the
following setting menu for download baudrate:
Please select your download baudrate:
1.* 9600
2. 19200
3. 38400
4. 57600
5. 115200
0. Return
Enter your choice (0-5):
Step 3: Choose an appropriate baudrate for downloading. For example, if you press 5, the baudrate
115200 bps is chosen and the system displays the following information:
Download baudrate is 115200 bps
Please change the terminal's baudrate to 115200 bps and select XMODEM protocol
Press enter key when ready